Disk bit



April 1933- H. w. FLETCHER 1,905,165

' DISK BIT Filed March 17, 1930 2 4/10 lNkiA TOR BY 11m A TTORNEY i withthe drill collar.

wardly extending legs 3 within which the cut- Patented Apr. 25, 1933UNITED STATES.

PATEN :-ome;

HAROLD w. FLETCHER, or HOUSTON, TEXAS, imam; TO informs moor. comm, or

nous'ron, TEXAS, A coarioaanon or Texas Application filed March 17,1980. Serial No. 436.335.

My invention relates to earth-boring drills employed in drilling deepwells and has particular application to drill bits of the socalled disktype in which the bore of the well is drilled by a plurality ofdisk-shaped cutters mounted rotatably upon a shaft supported in thedrill head.

A difiiculty experienced with bits of the disk-type, which are intendedparticularly for drilling soft formations, is that the disks may easilybecome clogged with disintegrated material which is not carried awayfrom the drill head sufliciently, thus preventing the rotation of thecutters.

It is an object of my invention to provide a drill bit havingdisk-shaped cutters thereon, said cutters being so formed as to engagethe bottom of the hole so as to obtain suflicient traction thereon tocause them to rotate free- It is also an object to so construct thecutters that the flushing fluid maybe employed in rotating the cuttersto clear them of material tending to clog thereon.

I also desire to construct the cutters so as to protect the shaft uponwhich the cutters are mounted so as to thereby prevent exces- F i 2 is acentral vertical section throughv the rill taken at right angles to theview' shown in Fig. 1.

Fig. 3 is a bottom plan view of the drill 1 head with the cuttersthereon.

In thedrawing I have illustrated my cut ters as mounted upon a.cylindrical head 1- having a threaded shank 2 for engagement- Thereare'two downflushing fluid to clear'the blades ofmud or material tendingto clog the cutters. When ter shaft 4 is mounted to support thediskshaped drill cutters 5. There is a central lon 'tudinal channel 6through the axis of the drifi to accommodate the flushing water which isdischarged directly downward upon the disks.

The cuttershaft 4 shown as being drical shaft extending diametrically othe head and supported at each end in openings 7 V in the legs of thebit. The ends of said openings 7 are countersunk at 8 to receive awasher 9 andthe end of the shaft is reduced in :diameteratlO to extendthrough thewasher9 and the end of the reduced portion is upset orriveted at 11 against the washer so. asito lock i the shaft securely inposition after the cutters have been placedthereon. When this shaft isto be removed the .upset end llof the shaft is chiselcdofl and the shaftremoved;

; The cutters5 are disk-shaped,having i outer faces flattened-at 12 to,engage with the bearing washer 18 adjacent theleg; Beyond the'flattenedportion the'cutter. is beveled at 13 soas to form a sharp cutting ed e14 presented inwardly. The inner sideo eachcutter has a hub.15 extendininwardly to a point spaced-slightly from t e hub of the adjacentcutter.This hub furnishes a bearing surface for the cutter and protectstheshafti 4 from wear, due to the discharge of flushing fluid throughthe channel.6.. a

To provide for suflicient traction to cause a positive rotation of thecutters and also to allow the flushing waterto assist in-the rotation ofthe cutters, I form, on the inner ,faces of each cutter,-va-nes or webs16, which, as shown :in Fig. 2, are tangential to the hub and areinclmed .fromthe end of said hub inwardly to the face ofthe-disk andtenni- 'nateon the face of the disk at a point spaced as seen in Fig.2..

slightly from the margin, These. vanes or blades on the disksieng ewith: the coral? which forms between the cutters on thebottom of thehole, and contact therewith assure sufiicient .tractlonto cause thecutters to positively rotate, The;

core coming in contact with broken up and disintegrated.

thesevanes is -These websare also ofuse in allowingthe it'is'noted thatthe bitisnot cutting in the usual manner due to the clog g of thecutters the bit may be raised 0 the bottom of the hole and the pumpsused to flush the mud in a strong current downwardly through the channel6 against the blades of the cutters. With the cutters ofi the bottom ofthe hole they are easily washed clear of material and the flushing waterstriking the webs 16 will cause the cutters to rotate and be uniformlyclearedof material on all sides. The bit may then a ain be dropped uponthe bottom of the ho f e and the drilling may continue. By the use of myparticular construction of t e cutters I am enabled to secure sufiicienttraction to cause rotation of the cut ters even though the cutters arenot ofi'set one from the other, and, further, when the cutters tend toclog, the cutters may be easily I washed clear of material in the mannerstated. By thus mounting the cutters in opposite relation 1 am enabledto'provide a simple. and economical structure which may be manufacturedcheaply and which is strong 20 and sturdy and able to withstand thestrains to which they are subjected. Also, even where the cutters aremounted directly opposite to each other, I am enabled to get rota- 'tionof the cutters. 26 What I claim as new is: f

1.- A drill head, a straight shaft sup orted thereon, disk-shapedcutters on said Is aft, means to space said cutters apart in oppositerelation on said shaft, and means on the in- 30 ner faces of saidcutters adapted to beacted upon by flushing fluid to rotate said cuttersfor the urpose stated. 1 i 2. A diill head, a straight shaft su' portedthereon, disk-shaped cutters on said shaft,

- means to space said cutters apart in opposite relation on' said shaft,and webs on the inner' faces of said cutters to be enga ed by flushingfluid to rotate said cutters an allow said cuttersto be cleaned.

4o 3. A drill head, a straight shaft supported on the forward endthereof, a pair: of diskshaped cutters having a bearing thereon, a meansto space said cutters apart, water passages in said head discharging onsaid outters, and webs formed on the inner faces of said diskstangential to the axis thereof and I positioned to be engaged by theflushing fluid to rotate the cutters.

4. A drill head, downwardly extending '50 legs thereon, a shaftsupported in said legs, I

opposite disk-shaped cutters rotatable *on said shaft, hubs on saidcutters spacing said cutters'apart, webs on said hubs and the disks'of'said' cutters, said webs tapering in width 7 outwardly andtangential to the axis of the 1 cutters, and water passages in said headdischar 'ng on said webs, whereby said cutters are c eaned and therotation thereof assisted.

In testimony whereof I hereunto afiix my o0 signature this 12th day ofMarch, A. D. 1930.

HAROLD W. FLETCHER.

